Measurements of π+\pi^+, π−\pi^-, pp, pˉ\bar{p}, K+K^+ and K−K^- production in 120 GeV/cc p + C interactions

This paper presents multiplicity measurements of charged hadrons produced in 120 GeV/$c$ proton-carbon interactions. The measurements were made using data collected at the NA61/SHINE experiment during two different data-taking periods, with increased phase space coverage in the second configuration due to the addition of new subdetectors. Particle identification via $dE/dx$ was employed to obtain double-differential production multiplicities of $\pi^+$, $\pi^-$, $p$, $\bar{p}$, $K^+$ and $K^-$. These measurements are presented as a function of laboratory momentum in intervals of laboratory polar angle covering the range from 0 to 450 mrad. They provide crucial inputs for current and future long-baseline neutrino experiments, where they are used to estimate the initial neutrino flux

Measurements of π±\pi^\pm, K±K^\pm, pp and pˉ\bar{p} spectra in 40^{40}Ar+45^{45}Sc collisions at 13AA to 150AA GeV/cc

The NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of nuclei of varied sizes. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of $\pi^\pm$, $K^\pm$, $p$ and $\bar{p}$ produced in $^{40}$Ar+$^{45}$Sc collisions at beam momenta of 13$A$, 19$A$, 30$A$, 40$A$, 75$A$ and 150$A$ GeV/$c$. The analysis uses the 10% most central collisions, where the observed forward energy defines centrality. The energy dependence of the $K^\pm$/$\pi^\pm$ ratios as well as of inverse slope parameters of the $K^\pm$ transverse mass distributions are placed in between those found in inelastic $p$+$p$ and central Pb+Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical (SMES, HRG) or dynamical (EPOS, UrQMD, PHSD, SMASH) models

Search for the critical point of strongly-interacting matter in 40^{40}Ar + 45^{45}Sc collisions at 150A Ge V /c using scaled factorial moments of protons

The critical point of dense, strongly interacting matter is searched for at the CERN SPS in $^{40}$Ar + $^{45}$Sc collisions at 150A Ge V /c. The dependence of second-order scaled factorial moments of proton multiplicity distribution on the number of subdivisions of transverse momentum space is measured. The intermittency analysis is performed using both transverse momentum and cumulative transverse momentum. For the first time, statistically independent data sets are used for each subdivision number. The obtained results do not indicate any statistically significant intermittency pattern. An upper limit on the fraction of correlated proton pairs and the power of the correlation function is obtained based on a comparison with the Power-law Model developed for this purpose

Multipurpose RF field vector controller for linear accelerators

The paper describes the design and the implementation of the flexible, multipurpose RF (Radio Frequency) field Vector Controller for the linear accelerators based on the superconducting technology. The implementation is done for the FPGA (Field Programmable Gate Array) based LLRF (Low Level Radio Frequency) control systems. The full process of the requirement analysis and the library implementation is presented. It is followed by the description of the controller's applications and the results of the performance tests. The controller fulfills the requirements of the various accelerator facilities and hardware platforms and can be easily adapted for the planned experiments to decrease their cost by avoiding expensive research and development phase

A Simple Approach to Data Analysis for the Detection of Hazardous Materials by Means of Neutron Activation Analysis

Neutron activation analysis is a well-known method for determining isotopic composition of different materials. Due to the non-destructive nature of the method it can also be used in homeland security application, for example an inspection of packages of unknown origin. For this purpose hazardous material detection system (SWAN) was built. The device has an automatic decision algorithm that analyze the spectrum of gamma rays of $\text{}^{12}C,$ $\text{}^{14}N$ and $\text{}^{16}O$. Characteristic ratio of these lines gives the requested answer. Using such a simple approach SWAN is able to obtain promising results

Excess of charged over neutral KK meson production in high-energy collisions of atomic nuclei

Collisions of atomic nuclei at relativistic velocities produce new particles, predominantly mesons containing one valence quark and one valence anti-quark. These particles are produced in strong interactions, which preserve an approximate symmetry between up ($u$) and down ($d$) quarks. In the case of $K$ meson production, if this symmetry were exact, it would result in equal numbers of charged ($K^+$ and $K^-$) and neutral ($K^0$ and $\overline K^0$) mesons in the final state. In this Letter, we report a measurement of the relative abundance of charged over neutral $K$ meson production in collisions of argon and scandium nuclei at a center-of-mass energy of 11.9~GeV per nucleon pair. We find that production of $\mathit{K^+}$ and $\mathit{K^-}$ mesons at mid-rapidity displays a significant excess of $(23.3\pm 5.7)\%$ relative to that of the neutral $K$ mesons. The origin of this unexpected excess remains to be elucidated.Collisions of atomic nuclei at relativistic velocities produce new particles, predominantly mesons containing one valence quark and one valence anti-quark. These particles are produced in strong interactions, which preserve an approximate symmetry between up ($u$) and down ($d$) quarks. In the case of $K$ meson production, if this symmetry were exact, it would result in equal numbers of charged ($K^+$ and $K^-$) and neutral ($K^0$ and $\overline{K}$$^0$) mesons in the final state. In this Letter, we report a measurement of the relative abundance of charged over neutral $K$ meson production in collisions of argon and scandium nuclei at a center-of-mass energy of 11.9~GeV per nucleon pair. We find that production of $K^+$ and $K^-$ mesons at mid-rapidity displays a significant excess of $(23.3\pm 5.7)\%$ relative to that of the neutral $K$ mesons. The origin of this unexpected excess remains to be elucidated

Excess of charged over neutral KK meson production in high-energy collisions of atomic nuclei

International audienceCollisions of atomic nuclei at relativistic velocities produce new particles, predominantly mesons containing one valence quark and one valence anti-quark. These particles are produced in strong interactions, which preserve an approximate symmetry between up ($u$) and down ($d$) quarks. In the case of $K$ meson production, if this symmetry were exact, it would result in equal numbers of charged ($K^+$ and $K^-$) and neutral ($K^0$ and $\overline{K}$$^0$) mesons in the final state. In this Letter, we report a measurement of the relative abundance of charged over neutral $K$ meson production in collisions of argon and scandium nuclei at a center-of-mass energy of 11.9~GeV per nucleon pair. We find that production of $K^+$ and $K^-$ mesons at mid-rapidity displays a significant excess of $(23.3\pm 5.7)\%$ relative to that of the neutral $K$ mesons. The origin of this unexpected excess remains to be elucidated

Measurements of higher-order cumulants of multiplicity and net-electric charge distributions in inelastic proton-proton interactions by NA61/SHINE

This paper presents the energy dependence of multiplicity and net-electric charge fluctuations in $p+p$ interactions at beam momenta 20, 31, 40, 80, and 158 GeV/$c$. Results are corrected for the experimental biases and quantified with the use of cumulants and factorial cumulants. Data are compared with the Epos1.99 and FTFP-BERT model predictions

Measurements of higher-order cumulants of multiplicity and net-electric charge distributions in inelastic proton-proton interactions by NA61/SHINE

International audienceThis paper presents the energy dependence of multiplicity and net-electric charge fluctuations in $p+p$ interactions at beam momenta 20, 31, 40, 80, and 158 GeV/$c$. Results are corrected for the experimental biases and quantified with the use of cumulants and factorial cumulants. Data are compared with the Epos1.99 and FTFP-BERT model predictions